Authorities allege the former pastor had methamphetamine mailed to him by his alleged co-conspirators in California, which he then sold out of his apartment, raking in more than $300,000 in sales.

On six occasions between September 2012 and January 2013, an undercover officer purchased methamphetamine from Wallin, according to U.S. Attorney David Fein.

Federal authorities also used wiretaps and surveillance to monitor the operation, Fein said.

"The hard work of the Drug Enforcement Administration and the Connecticut State Police in this case resulted in the dismantling of what we allege was a significant methamphetamine distribution organization that spanned from California to Connecticut," Fein said in a statement.

After Wallin was arrested on Jan. 3, the Diocese of Bridgeport released a statement saying that he had resigned as pastor of the parish in 2011, citing health and personal reasons, and was granted a sabbatical.

The diocese said that Wallin's "faculties for public ministry were suspended in May 2012, and he has not been reassigned."

Some of his former parishioners are shocked that the man they held in esteem as a "very honorable man of God" would get involved in such a scandal.

"I feel terrible about it. And we just keep praying for him, that's all," a parishioner told ABC New York station WABC in January. "If these allegations are true, we pray he repents, makes his peace with God, like we all have to."

Wallin's public defender did not immediately return a message left by ABCNews.com for comment.